Flat heat pipe with internal supporting element

ABSTRACT

An exemplary flat heat pipe includes a flat housing, a wick, a working fluid, and a supporting element. The wick is attached to an inner surface of the housing. The working fluid is contained in the housing. The supporting element is a woven screen made of metal wires and a plurality of through holes is defined therein. The supporting element is enclosed by the wick and opposite sides thereof bias the wick against opposite portions of the housing.

BACKGROUND

1. Technical Field

The present disclosure relates to heat dissipation, and more particularly to a flat heat pipe.

2. Description of Related Art

A commonly used flat heat pipe includes a flat housing, a wick attached to an inner surface of the housing, and a working fluid contained in the housing. However, the housing is thin and prone to sustain deformation from external force. When this happens, the normal functions and capabilities of the flat heat pipe are liable to be adversely affected.

It is thus desirable to provide a flat heat pipe which can overcome the described limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an assembled view of a flat heat pipe of an embodiment of the present disclosure.

FIG. 2 is a cross section of the flat heat pipe of FIG. 1, taken along line II-II thereof.

FIG. 3 is an isometric view of a supporting element of the heat pipe of FIG. 2.

DETAILED DESCRIPTION

Referring to FIGS. 1-2, a flat heat pipe of the present embodiment includes a flat housing 10, a wick 20 attached to an inner surface of the housing 10, a supporting element 30 enclosed by the wick 20 and biasing the wick 20 against the housing 10, and a working fluid (not shown) contained in the housing 10.

The working fluid is water, alcohol or other material having a relatively low boiling point, which can easily change to vapor when absorbing heat from the housing 10.

The housing 10 has both ends thereof hermetically sealed, and maintains a substantial vacuum therein. In the present embodiment, the housing 10 is made from a single body of material which is hermetically crimped at both ends thereof. The housing 10 is made of a high heat conductivity material such as copper. The housing 10 includes an elongated top plate 11, an elongated bottom plate 13, and two curved connecting plates 15. The bottom plate 13 is spaced from and parallel to the top plate 11. The two connecting plates 15 adjoin opposite lateral sides of the top and bottom plate 11, 13, respectively. The bottom plate 13 is an evaporating portion of the flat heat pipe, and is for thermally contacting a heat source (not shown) and absorbing heat therefrom. The top plate 11 is a condensing portion of the flat heat pipe, and is for dissipating heat transferred from the bottom plate 13.

The wick 20 is evenly distributed on the inner surface of the housing 10. In the cross-section of FIG. 2, the wick 20 has the shape of a flattened ellipse. The wick 20 has a porous structure, which may be in the form of grooves, sintered powder, screen mesh, or bundles of fiber. The porous structure enables capillary force to act to absorb condensed working fluid at the top plate 11 of the flat heat pipe and convey the working fluid to the bottom plate 13 of the flat heat pipe.

Referring also to FIG. 3, the supporting element 30 is a woven screen made of a multiplicity of metal wires 31 and a multiplicity of metal wires 33. The wires 31 are spaced from and parallel to each other, and wires 33 are spaced from and parallel to each other. The wires 31 and the wires 33 are interwoven. Preferably, material of the wires 31, 33 is the same as that of the housing 10. A plurality of holes 35 is defined in the supporting element 30 through which the working fluid flows. An average diameter of the holes 35 exceeds an average diameter of the pores of the wick 20. A density of the holes 35 of the supporting element 30 is in the range from 5˜50 mesh/inch. A width of the supporting element 30 is equal to that of the top plate 11 of the container 10, as measured between the two connecting plates 15. A length of the supporting element 30 is smaller than that of the top plate 11, as measured in a direction perpendicular to the line II-II of FIG. 2. The supporting element 30 is located at a middle of the housing 10. Top and bottom sides of the supporting element 30 elastically bias top and bottom portions of the wick 20 against the top plate 11 and the bottom plate 13 of the housing 10, to avoid deformation of the housing 10 when the top plate 11 or the bottom plate 13 is compressed. Thus, compressive resistance of the flat heat pipe is improved.

It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A flat heat pipe comprising: a flat housing containing a vacuum; a wick attached to an inner surface of the housing; a working fluid contained in the housing; and a supporting element enclosed by the wick, opposite sides of the supporting element biasing the wick against opposite flat portions of the housing, respectively, the supporting element comprising a woven screen of metal wires in which a plurality of through holes is defined.
 2. The flat heat pipe of claim 1, wherein material of the supporting element is the same as that of the housing.
 3. The flat heat pipe of claim 2, wherein the supporting element and housing are both made of copper.
 4. The flat heat pipe of claim 1, wherein the wick defines a plurality of pores therein.
 5. The flat heat pipe of claim 4, wherein an average diameter of the through holes of the supporting element exceeds that of the pores of the wick.
 6. The flat heat pipe of claim 1, wherein the wick has a porous structure in the form of at least one item selected from the group consisting of grooves, sintered powder, screen mesh, and bundles of fiber.
 7. The flat heat pipe of claim 1, wherein a density of the through holes of the supporting element is in the range from 5˜50 mesh/inch.
 8. The flat heat pipe of claim 1, wherein the housing comprises a top plate, a bottom plate, and two side plates adjoining the top plate and the bottom plate, and the opposite sides of the supporting element bias the wick at the top plate and the bottom plate of the housing, respectively.
 9. The flat heat pipe of claim 1, wherein the supporting element is made of a plurality of first metal wires and a plurality of second metal wires, the first metal wires are spaced from and parallel to each other, and the second metal wires are spaced from and parallel to each other.
 10. A flat heat pipe comprising: a flat housing comprising a top plate, a bottom plate facing toward and spaced from the top plate, and two side plates adjoining opposite sides of the top plate and the bottom plate; a wick attached to inner surfaces of the top plate, the bottom plate and the side plates of the housing; a working fluid contained in the housing; and a supporting element received in the housing, the supporting element comprising a woven screen of metal wires, with opposite sides of the supporting element biasing the wick against the top plate and the bottom plate of the housing.
 11. The flat heat pipe of claim 10, wherein the supporting element comprises a plurality of first wires and second wires, interwoven together.
 12. The flat heat pipe of claim 11, wherein the first wires are spaced from and parallel to each other, and the second wires are spaced from and parallel to each other.
 13. The flat heat pipe of claim 10, wherein a plurality of through holes is defined in the supporting element, the wick defines a plurality of pores, and an average diameter of the through hole exceeds an average diameter of the pores of the wick.
 14. The flat heat pipe of claim 13, wherein a density of the through holes is in range from 5˜50 mesh/inch.
 15. The flat heat pipe of claim 10, wherein the wick has a porous structure in the form of at least one item selected from the group consisting of grooves, sintered powder, screen mesh, or bundles of fiber.
 16. The flat heat pipe of claim 10, wherein the supporting element is located at a middle of the housing. 